I want to learn math on My own. Pre-algebra and beyond (The last math class I took was Pre-Calculus I at a community college. I finished with a B+/A-. But It's good to start from the basics and build on top of that). Is there an Android app or website with good material and practice problems that I could do on a day to day basis?

Don't say Khan. I already know of Them. Just wondering if there's anything else worth looking at.